This exam consists of 30 questions; true-false questions are worth 2
points each, three-choice multiple choice questions are worth 3 points
each, five-choice multiple choice questions are worth 6 points each.
The maximum possible score is 121. When the exam was given, the mean
was 83.9; the median was 84. Click here to see page1 page2
of the formula sheet that came with the exam.

(a)

(b)

(c)

### QUESTION 2***

Two identical bar magnets each have a wire loop around them. Loop
**a** is twice as large as loop** b**. Compare the magnetic flux
through the two loops.
(a) F_{a} > F_{b}

(b) F_{a} = F_{b}

(c) F_{a} < F_{b}

### QUESTION 3**

A loop of wire is moved at a constant speed over a fixed permanent
magnet as shown above. Which picture below best describes the EMF
generated in the loop as a function of position?

(a)

(b)

(c)

### QUESTION 4*

*This and the next three questions are about the following
situation:*
The particle spectrometer shown has a uniform magnetic field in the
region of the shaded box with direction perpendicular to the page and
magnitude |**B**| = 0.93 T. Particles #1 through #3, all with the same mass
m = 3.34 × 10^{-27} and same initial velocity v = 2 ´ 10^{6} m/s enter the box at the point
shown and follow the trajectories indicted.

Which particle has the greatest magnitude of charge?

(a) #1

(b) #2

(c) #3

### QUESTION 5*

The charge on the particle #3 is determined to be
*q*_{3} = +1.6 × 10^{-19} C. What is the
distance L labeled on the diagram?
(a) L = 0.022 m

(b) L = 0.048 m

(c) L = 0.090 m

### QUESTION 6*

What is the direction of the magnetic field?
(a) into the page

(b) out of the page

### QUESTION 7**

Particles entering the box are given their initial velocity
*v* by acceleration through an electric potential difference
*V*. If the potential difference is increased, the time spent by
the particle in the box will
(a) increase.

(b) decrease.

(c) stay the same.

### QUESTION 8*

*This and the next two questions are about the following
situation:*
The self-inductance of a long solenoid is *L* =
µ_{o}n^{2}V, where *n* is the number of turns
per unit length and *V* is the volume inside the solenoid. The
solenoid below has length l = 0.15 m and cross-sectional area *A* =
3.5 × 10^{-4} m^{2}. Its self-inductance is
*L* = 25 mH. A current *I* of 2.5 amps flows through its
coils in the direction shown in the figure.

Which way does the magnetic field point inside the solenoid?

(a) to the left

(b) to the right

### QUESTION 9*

How much magnetic energy, U_{m}, is stored in this
solenoid?
(a) U_{m} = 78 mJ

(b) U_{m} = 123 mJ

(c) U_{m} = 175 mJ

(d) U_{m} = 208 mJ

(e) U_{m} = 345 mJ

### QUESTION 10*

What is the magnetic field inside the solenoid?
(a) B = 14 mT

(b) B = 36 mT

(c) B = 48 mT

(d) B = 61 mT

(e) B = 88 mT

### QUESTION 11**

*This and the next question are about the following
situation:*
A single-turn rectangular wire loop of size 20 cm × 30 cm rotates
at a uniform rate of w = 50 rad/sec around the
z-axis as shown. There is a uniform magnetic field B in the
+y direction. The loop has a total resistance of R = 36 W.

At the instant shown, an induced current in the loop will

(a) flow clockwise.

(b) flow counterclockwise.

(c) not flow.

### QUESTION 12**

If the induced **rms** current in the loop is 0.04 A,
what is the strength of the magnetic field B?
(a) B = 0.17 T

(b) B = 0.29 T

(c) B = 0.55 T

(d) B = 0.68 T

(e) B = 0.79 T

### QUESTION 13*

*This and the next question are about the following
situation:*
The phasor diagram to the right yields information on a particular
series *RLC* circuit. It is only partially labeled, but you should
know from examining it the proper quantity that is referred to by each
number, given in ohms, in the drawing.

What is the total impedance, *Z*, of the circuit?

(a) *Z* = 12 W

(b) *Z* = 18 W

(c) *Z* = 36 W

(d) *Z* = 40 W

(e) *Z* = 65 W

### QUESTION 14*

If the inductance *L* = 0.02 H, what is the
capacitance?
(a) *C* = 0.21 mF

(b) *C* = 0.59 mF

(c) *C* = 3.17 mF

(d) *C* = 17.6 mF

(e) *C* = 33.3 mF

### QUESTION 15*

*This and the next two questions are about this series RLC
circuuit:*
What is the phase angle f for this
circuit?

(a) *f* = +73.8°

(b) *f* = +37.6°

(c) *f* = 0

(d) *f* = -37.6°

(e) *f* = -73.8°

### QUESTION 16**

What is the **peak power** delivered by the
generator?
(a) P_{pk} = 3.32 W

(b) P_{pk} = 4.13 W

(c) P_{pk} = 9.97 W

(d) P_{pk} = 14.3 W

(e) P_{pk} = 25.9 W

### QUESTION 17*

To bring the circuit closer to resonance, the frequency of
the oscillator should be
(a) increased.

(b) decreased.

### QUESTION 18***

*This and the next question are about the following
situation:*
Two identical loops are entering a region of uniform magnetic field
as shown. They are traveling with equal speed, but loop number 1 is
traveling down and loop number 2 is traveling up.

Compare the magnitude of the induced current in the two loops.

(a) I_{1} < I_{2}

(b) I_{1} = I_{2}

(c) I_{1} > I_{2}

### QUESTION 19**

The current in the two loops flow in the same direction
(e.g. both clockwise or both counter clockwise).
(T) True

(F) False

### QUESTION 20***

*This and the next question are about the following
situation:*
A loop carrying a clockwise current is located to the right of a long
straight wire carrying current up as shown.

What is the direction of the magnetic force on the current in the
segment **a-b** of the loop due to the current I_{1} in the
long straight wire?

(a) up

(b) down

(c) into page

(d) out of page

(e) zero

### QUESTION 21***

What is the direction of the net force on the loop due to
the current in the long straight wire?
(a) to the left

(b) to the right

(c) there is no net force

### QUESTION 22*

*This and the next two questions are about the following
situation:*
An *unpolarized* electromagnetic wave is incident at a series of
three linear polarizers, each with the polarization angle rotated at
45° with respect to the previous one.

Compare the frequency of the light from the police car that Jeep A
observes (f_{A}) with that observed by Jeep B (f_{B}).

(a) f_{A} > f_{B}

(b) f_{A} = f_{B}

(c) f_{A} < f_{B}

### QUESTION 26**

*This and the next question are about the
following situation:*
Three long co-planar parallel wires carrying currents are oriented as
shown.

The magnitude of the force on a 1 meter long section of the middle
wire (#2) from the currents flowing in the other two is:

(a) F = 1.08 × 10^{-4} N

(b) F = 3.34 × 10^{-4} N

(c) F = 6.61 × 10^{-4} N

(d) F = 7.90 × 10^{-4} N

(e) F = 8.41 × 10^{-4} N

### QUESTION 27*

The direction of the force on wire #2 is:
(a) up

(b) down

### QUESTION 28**

The figure below shows an edge view of two identical current-carrying
loops oriented as shown in a uniform magnetic field.

Compare the magnitude of the torque t
_{1 }on loop #1 with the torque t
_{2 }on loop #2 at the instant shown.

(a) t_{1} > t_{2}

(b) t_{1} = t_{2}

(c) t_{1} < t_{2}

### QUESTION 29**

*This and the next question are about the following
situation:*
A square coil with sides of 5 cm is wound with 20 turns of wire that
has resistance per length of 3 W/m. A coil
is placed in a uniform magnetic field oriented perpendicular to the
plane of the loop that is increased linearly from 0 to 4 T in 60
seconds.

Find the induced current in the loop while the field is
increasing.

(a) I = 0.278 mA

(b) I = 0.442 mA

(c) I = 0.792 mA

(d) I = 1.020 mA

(e) I = 1.421 mA

### QUESTION 30***

If the number of turns in the coil is increased, the
induced current:
(a) increases

(b) stays the same

(c) decreases

**Scoring of True-False (T,F) Questions:**
- If you mark the correct answer, you get 2 points.
- If you mark the wrong answer or if you mark neither answer, you get 0 points.

**Scoring of Multiple Choice I (a,b,c) Questions:**
- If you mark the correct answer, you get 3 points.
- If you mark a wrong answer or if you mark none of the answers, you get 0 points.

**Scoring of Multiple Choice II (a,b,c,d,e) Questions:**
- If you mark one answer and it is the correct answer, you get 6 points.
- If you mark two answers and one of them is the correct answer, you get 3 points.
- If you mark three answers and one of them is the correct answer, you get 2 points.
- If you do not mark the correct answer, or if you mark more than three answers,
or if you mark none of the answers, you get 0 points.